NWO ENW M “Wired for Company: Decoding How Social Cues Override Environmental Signals in Drosophila melanogaster”

Awardee: Jean-Christophe Billeter (University of Groninge/GELIFES)

Project Description:
Being around others has powerful effects on an individual’s biology. It can reduce pain, slow disease, and even help live longer. Yet, despite these clear effects, we do not understand how the brain and body detect the presence of others and change behavior and physiology in response. This project aims to uncover how social presence alters biological function, using the fruit fly (Drosophila melanogaster) as a powerful model system. Fruit flies may seem simple, but they live in social groups and, like most animals, respond strongly to being alone or with others. We discovered that when female flies are alone, the presence of light prevents them from laying eggs—but when other flies are nearby, they lay eggs even under bright light. This shows that the flies can “sense” the presence of others and that this social information can override environmental cues. We now seek to understand how this happens in the brain. We will identify the sensory pathways that detect light and other flies, the brain circuits that combine this information, and the hormones and motor programmes that ultimately control egg-laying. Fruit flies are uniquely suited for this work because we have detailed maps of every brain connection and tools to study individual neurons and hormones with great specificity. By revealing how social environments influence biology in fruit flies — from sensory cues to behavior—this research addresses a fundamental biological question with wide relevance: how individuals are influenced by others. This knowledge is especially relevant today, as societies grapple with the health effects of social disconnection, as habitat fragmentation reduces wild animal social interactions, and as the welfare and productivity of farm animals depends on their social environment.